Air-brake system



D. R. MAcBAIN.

MR BRAKE SYSTEM.

APPLICATION FILED OCT-1B, 91p.

' 1,373,365, Patented May 17,1921.

2 SHEETS-SHEET 1.

D. R. MACBAIN.

AIR BRAKE SYSTEM.

AEPUCATION HLED OCT-18, 1919.

Patented May 17, 1921.

2 SHEETSSHEET 5' Int I 816 NA L PIPE 9 MAIN EESEPVO/E atwe'nboz wm l Nl'l' ED STATES PATET FEEQE.

DONALD E. MAGBAIN, OF CLEVELAND, OHIO.

- AIR-BRAKE SYSTEM.

' Specificationof Letters Patent.

Patented May 17, 1921.

Application filed October 18, 1919. Serial No. 331,609.

T 0 all whom it may concern Be it known that I, DONALD R. MAOBAIN, citizen of the United States, residing at 1921 E. 97th St., city of Cleveland, county of Cuyahoga, State of Ohio, have invented certain new and useful Improvements in Air-Brake Systems, of which the following is a specification.

This invention relates to an engineers auxiliary brake controlling system, its object being to provide means whereby an engineer may control the setting of the brakes upon the several cars of a train even though one or more angle cocks in the train line is, or are, closed. v

The system constituting the subject matter of the present invention is intended to operate in conjunction with the standard automatic air-brake systems commonly in use. It is well known that in these systems the setting of the brakes is effected by a reduction in pressure in the train line. It is a known fact that many serious and destructive wrecks have been occasioned by one or more of the angle cocks of the train line being inadvertently left closed. The present invention, therefore, aims to pro vide means through which the engineer may vent the train line in the rear of the closed angle cooks, the setting of the brakes being thereafter effected by the usual service cylin der and auxiliary reservoir pressure of the standard automatic brake mechanism.

Broadly stated the invention contemplates providing a by-pass around the usual reducing valve of the signal line of the train and locating in said by-pass a stop cock accessible from the engineers' seat, so that if the engineer finds that his control of the brakes is interfered with by a closed angle cock he may, by opening the stop cock in the by-pass, throw the full main reservoir pressure into the signal line, this increase of pressure above normal in the signal line acting upon'pistons in auxiliary cylinders to open the conductors valve in the several cars and bring about the necessary reduction in pressure in the train line to cause the brakes on said-cars to be set in the usual'and well known way.

' 'The invention further contemplates the provision of means for conducting the increased pressure in the signal line to the service cylinders of the several cars after the conductors valves have been operated asset forth to thereby augmentthe pressure reach the same.

Fig. 3 is a' vertical section through a special valve used in the connecting pipe between the triple valve and the service cylinder; and

Fig. 4 is a diagrammatic view illustrating the by-pass around the reducing valve of the signal pipe.

In the drawings 5 designates the main" reservoir, 6 the signal pipe and 7 a reducing valve by which the normal one hundred thirty pounds pressure of the main reservoir is reduced to the usual fifty pounds pressure in the signal pipe. A by-pass 8 leads around the reducing valve and has a stop cock 9 located in its length, said stop cock being located in'such proximityto the engineers seat that the engineer may readily Referring now to Figs. 1 and 2, 6 designates an extension from the train signal pipe which leads to the bottom of an auxiliary cylinder 10, it being understood that the structure of Figs. 1 and 2 is duplicated upon each car of the train. Slidable within each of the auxiliary cylinders 10 is a heavily weighted piston 11 which carries a valve disk 12 at its bottom that is adapted to have a seating upona valve seat 13 so that under normal conditions the extension 6 of the signal pipe will be closed and the normal line pressure will be maintained therein, but if, as previously explained, the pressure in this sig nal line is suddenly increased by the opening of the stop cock in the by-pass by the engineer this increased pressure will act be vented bythe opening of the usual conductors valve 19. It is well known that when the train line is vented and the pres sure is reduced a triple valve 20 functions to permit pressure fluid to pass from an auxiliary reservoir, not shown, to the service cylinder 21 of the car. However, it is possible that, by reason of an angle cock raving been closed, inadequate pressure will exist in the auxiliary reservoir and to provide for this contingency I provide a special valve 22. By referring to Fig. 3 it will be seen that this special valve comprises a casing 24: having valve seats 25 and 26 1 be closed by the valve disks 2'? and 28 re spectively. These valve disks are mounted upon a stem 29 and said stem carries a pis ton 30 that is mounted in a cylinder 81. The cylinder 31 is threaded 32 into engagement with the casing 241-. A spring 38 tends to elevate the piston 30. A cap 3d is thread ed into the upper end of he cylinder 31 and this cap is tapped for the reception of a pipe 85 that leads to the side of the auxiliary cylinder 10 and has connection with said cylinder 10 at a point somewhat above the bottom of the cylinder. Consequently after the piston 11 has been moved upwardly a predetermined distance it uncovers the port 36 to permit the full main reservoir pressure to pass through pipe 35 and enter the upper portion of the cylinder 31 where this pressure acts upon the piston 80 and forces this piston downwardly against the action of the spring 33, thereby seating disk 28 upon seat 26 and unseating disk 27 from seat 25. It is to be noted that the stem 29 is tubular throughout the upper portion of its length as indicated at 37 andthat the bore thereof communicates witlrlateral port 38. Vvhen the piston 30 moves downwardly under the influence of the main reservoir pressure the ports 38 are brought into communication with the chamber 24 of the valve casing 21, and the main reservoir pressure may then pass through the port 38, chamber 24; and the right hand portion of the pipe 23, Fig. 1, to theservice cylinder thereby insuring the necessary degree of pressure in said service cylinder to effectively set the brakes.

As soon as the engineer closes the stop cock in the bypass and no additional pres sure is supplied to the signal line except what passes the reducing valve the pressure in the signal line is quickly restored to normal by leakage through a minute port 40 formed in the bottom of the auxiliary cylinder 10.

It will be understood that the weight of the piston 11 is designedly made such as to maintain the proper degree of pressure in the signal line. In other words, the weight of this piston is such that it will not be lifted until the pressure in the signal line exceeds normal.

t is manifest that instead of making this piston a weighted one a spring could'be adapted to used, though I prefer the construction shown. The disk 27 and seat 25 constitute a valve structure which prevents pressure in the pipe 23, during the ordinary application of the brake from leaking back through pipe 35 to the auxiliary cylinder 10.

It is within the scope of my invention to utilize a separate pressure line, instead of the signal line, if desired, though the utilization of the signal line in the manner set forth renders the installation of this system a very simple and economical matter.

It is to be understood that the invent-ion is not limited to the precise construction set forth but that it includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims. 7

Havin described my invention, what I claim is:

1. The combination with an automatic air-brakesystem operable upon reduction of pressure in the train line, of individual pressure operated venting elements in each car for said train line having connection with the signal line of the train and means controllable from the engine cab for creating a greater than normal pressure in said signal line to thereby cause the actuation of the individual venting elements.

2. The combination with an automatic air-brake system operable upon reduction of pressure in the train line, of individual pres sure operated venting elements in each car for said train line, a signal line connected to the pressure operated elements, means for preventing the operation of said elements by the normal pressure of the signal line and means controllable from the engine cab for creating a greater than normal pressure in the signal line to thereby operate said venting elements. r

The combination with an automatic air-brake system operable upon reduction of pressur in the train line, and including a main reservoir upon the engine, a signal line connected to said reservoir through a reducing valve, a by-pass leading from the main reservoir to the signal line around said reducing valve, a stop cock in said by-pass, in-

dividual. venting elements for the train line in the several oars, pressure operated actuating means for the venting elements connected to the signal line which are not operable under the normal pressure of the signal line but operate upon the introduction of excess pressure to said signal line from the main reservoir.

4. The combination with an automatic air-brake system operable upon reduction of pressure in the train line, of individual venting elements in each car for said train line and, actuating means for said venting elements comprising cylinders pistons operable thereln, a pressure line leading to the cylin;

ders beneath said pistons and valvular means upon said pistons for closing said pressure line until the pressure therein exceeds a predetermined degree.

5. The combination with an automatic air-brake system operable upon reduction of pressure in the train line and including individual train line venting elements in the several cars and individual service cylinders upon said cars, of pressure operated members for actuating the venting elements, a pressure line controllable from the engine for supplying pressure to said members and means for conducting the actuating pressure from said members to the service cylinders.

6. The combination with an automatic air-brake system operable upon reduction of pressure in the train line and including individual venting elements in the several cars of a train and also including the usual service cylinders and triple valves upon the several cars, of a piston operated valve disposed in the connection between the service cylinder and the triple valve and operable under pressure to close that part of said connection leading to the triple valve and to admit the actuating pressure to the service cylinder, auxiliary cylinders in the several cars, pistons therein, said individual train lin venting elements adapted to be actuated by the movement of said pistons, a connection between each of said pistons and the corresponding pressure actuated valve for conducting pressure from the former to the latter, a signal line leading to the auxiliary cylinders, means for maintaining the signal line closed with respect to said pistons until the pressure in the signal line exceeds normal and means controllable from the engine cab for admitting a greater than normal pressure to the signal line to thereby actuate the pistons in the auxiliary cylinders to operate the train line venting elements and to thereafter admit such pressure to the service cylinders.

7. The combination with an automatic air-brake system operable upon reduction of pressure in the train line, of individual train line venting elements in each car, auxiliary cylinders in the several cars, pistons in said cylinders the movement of which operates said venting elements, a signal line having connection with the several cylinders, means carried by the pistons in the auxiliary cylinders for maintaining the signal line closed with respect to said auxiliary cylinders until the pressure in said signal line exceeds normal, a main reservoir to which the signal line is connected, a by-pass, a controlling valve in said by-pass, a connection between the signal line and the main reservoir including a reducing valve whereby the pressure may be maintained at normal in the signal line through the medium of the reducing valve or may be increased to considerably above normal through said by-pass, said airbrake system including the usual cylinders, triple valves and connections therebetween upon the several cars, a piston operated valve in each or" the connections between the triple valves and the service cylinders of the several cars and a connection between said piston operated valve and the auxiliary cylnesses.

DONALD E. MAcBAIN.

Witnesses:

C. R. GAUL'r, BERTHA M. ENNIS. 

